Wednesday, January 10, 2007 - 3:15pm
Dr. Wolfram Schmidt (Univ. Würzburg):
Abstract. The significance of subgrid scale models in fluid dynamical simulations is a controversial topic, particularly, in astrophysics. It is quite customary to apply the 'minimal solution', meaning that numerical dissipation is supposed to take care of everything on small, unresolved scales. An example for which the minimal solution does not suffice is turbulent combustion in type Ia supernovae. Based on my experience with adopting a so-called localised subgrid scale model from engineering, I will outline the difficulties and implications for this particular application. Moreover, I will try to motivate why the effort of implementing non-trivial subgrid scale models will pay off for virtually all kind of turbulent flows in astrophysics.